What it means
A control module has stopped receiving expected network messages from hybrid/EV battery pack current sensor C. The effect on battery current monitoring and control depends on the vehicle's system design.
At a glance
- Usually lights the warning light of the system that lost communication
- The engine or gearbox may go into limp mode
How it works
Hybrid/EV battery pack current sensor C measures current in the high-voltage battery pack and sends that information over the vehicle network. U064C sets when a control module no longer receives expected messages from sensor C, so the system may lack that sensor’s current data and limit vehicle operation.
Common causes
Most likely first.
- Bus wiring open or shorted
- Module without power or ground
- Module failed
Symptoms
- Warning light or message related to the affected system
- Battery current data may be unavailable
How to diagnose it
- Scan all modules and save freeze-frame data, including any battery, current-sensor, isolation, or network communication codes.
- Check live data for battery pack current sensor C and confirm whether its reading is absent or invalid.
- Inspect accessible low-voltage connectors and network wiring associated with sensor C for damage or corrosion; do not touch high-voltage components.
- Check the sensor C module’s low-voltage power and ground circuits against the manufacturer’s specification.
- Test the network wiring serving sensor C for opens or shorts using the vehicle wiring information.
- If wiring and supplies pass, verify communication and sensor C module operation using the manufacturer’s procedure.
Common fixes
- Reconnect or clean an accessible low-voltage connector for current sensor C.
- Repair damaged low-voltage network wiring to sensor C.
- Restore the sensor C module’s low-voltage power or ground supply.
- Replace the current sensor C module if its circuits are sound but network communication remains absent.
Can I keep driving?
Stop safely and follow the vehicle’s instructions if a battery, hybrid-system, or reduced-power warning appears; missing current data may restrict or interrupt propulsion. Do not access high-voltage components, and arrange prompt diagnosis.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.